"Thousands of Coloradans have been denied the right to vote because of a policy that may violate federal law. Colorado Secretary of State Mike Coffman has authorized county clerks to purge newly registered voters under the so-called 20-day rule. Here, county clerks must send non-forwardable letters to newly registered voters. If the mail bounces back to the clerks, then they must remove the voter applicants' names from the rolls. Voting rights advocates say that the policy violates the 1965 National Voting Rights Act."

Voting rights advocates say that the policy violates the 1965 National Voting Rights Act. The Advancement Project, a voter protection organization, filed suit on behalf of several other groups against Coffman to halt the practice and reverse course on other voter purges. According to the suit, 3,291 of these 20-day applicants have been removed since August 2007.

"We consider these voters to have been registered when they are entered into the SCORE database," Jenny Flanagan, executive director of Colorado Common Cause told the Colorado Independent, referring to the state's new voter database. "They have met the other requirements for registrations and they are taken off when the cards are returned. There are examples of when there could have been an error."